1. Field of the Invention
The present invention concerns an electrostatic coating facility for electroconductive coating materials used for electrostatic coating of an aqueous coating material, a slurry coating material, metallic coating material or the like to objects to be coated which are conveyed continuously by way of a conveyer.
2. Description of the Prior Art
In a case of electrostatically coating an aqueous coating material by applying a high voltage to a coating machine while grounding an object to be coated to the earth, it is necessary to provide an insulative countermeasure to a system leading to the coating machine for supplying an aqueous coating material in order to prevent the high voltage applied to the coating machine from leaking (refer to Japanese Patent Laid Open Sho 55-114366 and 56-141869). However, in a multicolor coating apparatus adapted to conduct coating under color change of coating materials for as much as several tens of colors, there has been a trouble of insulating supply pipes, reservoirs, etc. on every colors of coating materials.
Therefore, in a multicolor coating for automobiles and like other objects, electrostatic coating by using insulative resin coating materials that consume a great amount of deleterious organic solvents have been predominantly and the use of aqueous coating materials, although free from such public pollutions, has been hesitated at present.
However, environmental protection actions have been raised world-wide in recent years and, also in the coating industry, regulation for the use of organic solvents such as hydrocarbons that cause environmental pollutions has been discussed and coating by means of aqueous coating materials not using thinner or the like has been recommended.